librcad 2.2 image

hello i am new of forum
and  i want to learn
librecad 2.2

i have ubuntu 18.04.4

the problem is due to the image as reference,

i have a image reference in  a layer
and in other layer a have Reference line
, when the mouse go on the image
 librecad is bloched
 and is impossible  make other things
i must to close librecad.

is a bug?

I'm not sure to understand you right. Please explain more what you are are trying to do.
Is it a drawing you have made yourself with LibreCAD or is it coming from a different system?
Maybe snap problem: be sure to have Free Snap on, that dotted cross icon.
Or are you trying to select a line lying under/within  the image? There is the problem that in this case always the image is selected then. This is a bug. It even happens when the image layer is locked. You have to switch it to invisible to prevent it to be selected. You can select the line only by pulling up a window around it. If this is of use depends on the operation you want to do.

the problem is the snap